Expansible locking key



Dec. 28 1926.

G. A. OcoNNr-:LL

EXPANSIBLE LOCKING KEY Filed May 19. 1925 INVENTOR George HOVGOnne/l WITNESSES w wl my.

ATTO EY Patented Dec. ZS, 1926.

1,612,769 TENT QFICE.

GEORGE A. OCOS'TITELI, OF l/VORCESTER, MASSACHSET'IS, ASSIGNOR T0 JOHN E. OCNNELL, OF VIGRCESTER, MASSACHUSETTS.

EXPAITSIBLE LOCKING KEY.

Application filed May 19, 1925.

My invention relates to machine elements and more particularly to an eXpansible locking key adapted particularly for connecting a rotatable body to a shaft.

In accordance with the prior practice, a

heavy drum is ordinarily keyed to its rotating shaft by providing both the shaft and the hub of the drum with opposed keyways and then driving a key into the keyways. It is necessary that this key have a fairly close driving t in the keyways and that it be driven in firmly to prevent relative movement between the connected parts. Hence, when it is desired to remove the drum from its shaft, considerable difficulty is ezperienced in removing this large key from the keyway into which ithas been driven.

It is accordingly the main object of my invention to overcome this difficulty and to provide an expansible key which may be cheaply manufactured and quickly assembled and which may be employed to connect two rotatable bodies together and which will hold them firmly and rigidly together as long as desired and yet may be quickly and easily removed to disconnect them.

With this and other obiects in view, as will be apparent to one skilled in the art, my invention resides in the combination of parts 3 set forth in the specification and covered by the claims appended hereto.

Referring to the drawings in which like reference numerals indicate like parts:

Figure 1 is a section partly in elevation and broken away showing the central hub of a drum connected to a shaft by means of expansible key;

Fig. 2 is a top plan view of the key; and

Fig. 3 is a perspective view cut centrally on a vertical plane showing the construction of the key.

In accordance with my invention, I propose to provide a key which is made of separable parts which may he moved relative to one another to form an eXpansibl-e device so arranged and constructed that the key may be easily locked in position in a ke-yway. One embodiment of my invention., as illustrated in the drawings. comprises wedge- 50 shaped members having` plane faces sliding in the opposed keyways and beveled faces slidably mounted in parallelism and so arranged that sliding one member on the other serves to expand the kev laterally while maintain- 55 ing their outer faces parallel. These parts Serial No. 31,401.

may be held together and adjusted by screwthreaded means which are so arranged that the members may be moved relative to each other to expand the key laterally or be disassembled.

As shown in the drawings which illustrate one embodiment of my invention, the hub of a drum may be fastened to a spindle 11 by providingthem with` opposed keyways 12 and 13 respectively for insertion of the key shown in the drawings.

The key as a whole is made to fit the keyways with a slight amount of Clearance in one direction, preferably radially of the spindle, and is provided with a fairly snug lit in the other direction so that there will be no plav between the bodies connected together. The device as illustrated is made up of three wedge-shapedparts, the middle one 15 having a lower plane face 16 fitting in the keyway of one of the members 11 and two beveled faces 17 and 18 sloping upwardly towards each other. Slidably mounted on the two beveled faces are the end members 19 and 20 having plane top facesV 21 and 22 respectively, which tit against the bottom of the keyway in the drum 10 and are maintained parallel with the bottom surface of the central member 15.

In order` to connect these parts together and permit moving them. one relative to another, I employ a screw-threaded member which may be arranged in various ways to move the end parts up the inclined planes of the central portion. As illustrated. I prefer to employ a bolt 25 which passes through aligned openings in the various members. The other end of the bolt is preferably fastened to the wedge-shaped member 19 by heading over the end of the bolt 27 to prevent it pulling out. and if desired, relative rotation between the bolt and this member may be prevented by means of the pin 28, suitably fitted into a hole bored through the key to contact with both the bolt and the outer part 19. The bolt may Ht tightly in the member 19, but the centrally disposed openings in the members 15 and 20 are made .larger than that in 19 so that the bolt may move laterally relative to these two parts as the key is expanded. The screw-threaded end of the bolt projects outwardly beyond the end of the key member 2O and has a nut 29 mounted thereon which is adapted to hold the parts assembled and move them relative to one another. In order that the key may be easily removed from the keyway, I preferably provide the outer end of the member' 22 with a lug so arranged that it may be used fer prying the key from the keyivay.

The operation of this device Will be obvious from the above disclosure. YVhen it is desired to lock a drum to a shaft by means of the key, the nuts 29 are loosened on the bolt and the key is slid Vinto place in the keyWay, until the head 30 is positioned close to the drum 10. rlhen upon tightening the nut 29, the members 19 and 20 Will be moved up the inclined planes of the part- 15, thereby making the lrey Wider and serving to clamp it tightly against two opposed faces 0f the two keyvvays. To remove the key, it is merely necessary to loosen the bolt 29 slightly and then draw the parts out by pulling on the lug 30.

lt Will be obvious that various changes may be made in this device Wit-hin the scope of the appended claims.

Having thus describe-d my invention, What I claim as new and desire to secure by Letters Patent is z- 1. An eXpansible key to fit in a keyway and connect a rotatable member to a shaft comprising a central member and two end members which When assembled have tWo outer parallel plane faces and inner' parallel beveled faces so arranged as to slide one on another and expand the key laterally and a screw-threaded device connected to one member and passing through the. others which is arranged to draw the members together.

if. lin expansible hey to connect a shaft and a member mounted thereon which have opposed keyWays, comprising a central member having yone plane face fittingV in a key Way and opposi'tely sloping beveled faces, tivo wedge-shaped outer members, each having a plane face fitting in a keyWay and a sloping face slidably mounted on one of the beveled faces of the central member, a threaded member fastened to one of the outer members and passing loosely through the yother two, and a nut on the threaded member, said parts being so arranged that tightening the nut serves to expand the key laterally to bind it in the lreyvvays. Y

Signed at `Worcester, Massachusetts, this 14th day of May 1925.

GEORGE A.. @GONNE-LL. 

